建筑装饰用铜合金的表面钝化工艺与性能研究

采用化学浸渍法在装饰用H62铜合金表面制备了不同转化膜，优化了单一稀土盐和复合（Ce+La）盐转化膜的钝化液配方，对比分析了未加稀土盐、单一Ce盐、单一La盐和（Ce+La）盐试样的耐蚀性能和作用机理。结果表明，单一稀土盐的钝化液中硝酸镧/硝酸铈含量为8%时的转化膜具有最佳的耐腐蚀性能；复合（Ce+La）盐最优钝化工艺为硝酸镧/硝酸铈=4/4 g/L、C₆H₅N₃浓度15 g/L、Na₂MoO₄浓度2 g/L、C₆H₈O₇浓度13 g/L、C₇H₆O₆S.2H₂O浓度9 g/L、SDBS浓度0.2 g/L、钝化温度48℃、钝化时间4 min；不同转化膜试样的硝酸点滴、中性盐雾、静态浸泡腐蚀和电化学腐蚀性能测试结果具有一致性，即耐性能从低至高顺序为：未加稀土盐<单一Ce盐<单一La盐<（Ce+La）盐，在钝化液中添加稀土盐有助于提高转化膜膜层厚度，并增强转化膜的耐蚀性能，且复合添加（Ce+La）盐可获得相对单一稀土盐更好的钝化效果。

Study on Surface Passivation Technology and Properties of Copper Alloy for Building Decoration

Different conversion films were prepared on the surface of H62 copper alloy for decoration by the chemical impregnation method,and the passivation solution formulations of single rare earth salt and composite(Ce+La) salt conversion films were optimized.The corrosion resistance and mechanism of the samples without rare earth salt,single Ce salt,single La salt,and (Ce+La) salt were compared and analyzed.The results show that the conversion film with 8%lanthanum nitrate/cerium nitrate in the passivation solution of single rare earth salt has the best corrosion resistance;the optimal passivation process of composite (Ce+La) salt is lanthanum nitrate/cerium nitrate=4/4 g/L,C₆H₅N₃ concentration 15 g/L,Na₂MoO₄ concentration 2 g/L,C₆H₈O₇ concentration 13 g/L,C₇H₆O₆S.2H₂O concentration 9 g/L,SDBS concentration 0.2 g/L,passivation temperature 48℃,passivation time 4min.The results of nitric acid drop,neutral salt spray,static immersion corrosion,and electrochemical corrosion test of different conversion film samples are consistent;that is,the order of the resistance from low to high is:without rare earth salt